HV & LV Cable Insulation Resistance Testing

LV & HV Cable Insulation

Accurate Testing for High and Low Voltage Cable Integrity

We provide professional insulation resistance testing for high voltage and low voltage cables across the UK. Our testing services help identify degradation, moisture ingress and electrical faults before they lead to breakdown or failure.

Why Insulation Testing Is Essential

Cable insulation can deteriorate over time due to heat, moisture, mechanical damage or age. Regular insulation resistance testing ensures your electrical network remains safe, efficient and fully compliant with UK standards.

Key benefits of insulation resistance testing:

  • Early detection of insulation failure
  • Improved electrical system safety
  • Reduced risk of unplanned outages
  • Validation of new cable installations
  • Support for preventative maintenance planning

We carry out testing as part of new installations, fault investigations and ongoing asset management.

What We Test

Our engineers test both new and existing cables using calibrated, industry-approved equipment. Tests are conducted safely, with results recorded for each phase and conductor.

We test:

  • LV power and control cables
  • HV distribution and feeder cables
  • XLPE, PILC and armoured cables
  • Single and multicore cables
  • Underground and overhead runs

Test results are compared against recommended insulation values and any irregularities are flagged for investigation.

Fully Documented & Compliant

Every test includes a detailed report showing readings, test methods, conditions and recommendations. We follow all current UK electrical testing guidelines and carry out testing as part of scheduled maintenance or standalone services.

Frequently Asked Questions

It measures how well the cable insulation prevents leakage of current. Low values can indicate breakdown, contamination or moisture within the insulation.

Yes. We carry out insulation resistance testing on both low voltage and high voltage cables, whether part of a new install or existing network.

Absolutely. We test both short and long-distance cable runs, using appropriate voltage levels and equipment for each type and rating.

Yes. You will receive a full test report with insulation values, equipment used, and any recommendations if abnormal results are found.